Dore mace



G. C. TAFT.

Crank for Boring Machines.-

No. 72,114. 4 Patented Dec. 10, I867.

Wneases:

guitar grates gaunt @ffimr TO ALL WHOM IT MAY CONCERN: H

Be it known that I, GEORGE C. 'JAFT, of Worcester, in the Shit. v. assachusetts, have invented and made GEORGE 0. .YTAFT, OF WORCESTER, MASSAOHUSE'ITS, ASSIGNOR T0 THEO} DORE MACE, 0E SING SING. NEW YORK.

Letters Patent No. 72,114, dated December 10, 18672 IMPROVEMENT IN VARIABLE eEANK ron BORING-MACHINBS.

a certain new and useful Variable Crank for Boring-Machines, &c.; and I do hereby declare the following to be a full, clear, and exact description of the said invention, reference being had to the annexed drawing, melting part of this specification, wherein I have reprosented a boring-machine with my improved critnks applied thereto. In the boring-machines heretofore constructed, the cranks are of a. definite length, and hence inlboring large-sized holes the labor is very severe, because there is not sufiicient leverage by the cranks, and the conteary is the case when boring small holes, there being a less of time, because the workman's hands have tomove through an unnecessarily large circle. V

The nature of my said invention consists in two variahle cranks, at right angles to each other, constructed in such a manner. that the handle may be placed at any desired distance from the axis, ond combined with boring-mechanism thereby :1 large leverage can beBbtained forheavy work, or a short leverage employed for light work, so-that the hands of the workman will only have to describe the proper-sized circle to produce the power required in rotntingthe auger or drill. I i

In .the drawing, a represents the base, b'the standards, and c the slides, receiving the frame 01, spindle e, angerf, horizontal shaft g, and gearing it. These parts being of any usunl or desired character, do not require further description as to their construction or mode of operation, they being well known and in use.

My varia'ble cranks are eachforme'd of an arm, 2', keyed or otherwise secured upon the endsof the shaft, and at the end of the arm z' is a, hub, is, standing at right angles to the-shaft g, and provided with a clampingbolt or screw,'l. m is a. rod, either round or polygonal, passing through the hubk, and n is a handle, of any suitable size or shape, standing elf at right angles to-the rod 122, and thesecranks are to be placed at rig-ht angles to eaehother on the ends of the shaft It will now be understood that the crqnk-han'dle n can be placed at any desired distance from theaxis or shaft g by sliding the rod -m in the hub is, and clamping it, and thereby the leverage applied to rotate the drill or anger can be varied as desired for the purposes aforesaid.

What I claim, and desire to secure by Letters Patent, is-

The two variable cranks, constructedasspecified, and applied in the manner shown, to the shaft or axis of the boring-machine, as and for the purposes set forth'..

In witness whereof, I have hereunto set my signature, this twentieth day of May, A. 1867.

GEO. C. TAFT.

Witnesses: t

GEO. C. Terr, Jr.,

RUBIN CARPEN TER. 

